Well... smile generates more smile. People tend to respond what's your mood... if you smile they smile except of course for those people who is ammoyed at you, If you smile at them, they will even frown and despise you more. lol. Even so, just keep on smiling... coz being in a state of joyful mood can always produce the best.
As for me, i always plastered smile on my face to everyone to brighten up my day and to others. We'll never know someones' gonna fall in love with that smile. lol